Ground overcurrent control system and methods of using same

ABSTRACT

A ground overcurrent control system includes ground circuit with a first section and a second section. The first section is electrically connected to a ground member of an electrical connector and the second section is electrically connected to a ground reference. A switch element is positioned between the first section of the ground circuit and the second section of the ground circuit. A controller is configured to determine the current within the ground circuit while current is passing through the switch element and, upon the current exceeding a current threshold, the switch element is modified to an open condition. Upon determining that the voltage between the first section of the ground circuit and the ground reference is less than a voltage threshold, a command is generated to modify the switch element back to a closed condition.

RELATED APPLICATIONS

This patent application claims the benefit of U.S. provisional patentapplication Ser. No. 62/268,739, filed Dec. 17, 2015, which isincorporated herein by reference.

TECHNICAL FIELD

This disclosure relates generally to the field of electrical deviceprotection and, more particularly, to a system and method of controllingexcessive current on ground circuits associated with a device.

DESCRIPTION OF RELATED ART

The use of electronic devices such as smartphones, tablets, musicdevices, and other portable devices has become more prevalent.Multimedia stations and other components often include a plurality ofpower receptacles or ports for charging such devices. In many instances,all of the power receptacles or ports may not have a device connectedthereto. In some instances, a cable assembly may be plugged into one ofthe power receptacles or ports but is not connected to an electronicdevice. The unplugged end of the cable assembly may have an exposedground or shield member.

Further, in some instances, a cable assembly may not be plugged into oneof the power receptacles or ports so that a power terminal or contact isexposed. For example, a cylindrical 12 V power receptacle includes acylindrical ground member that surrounds a central power terminal orcontact. If the unplugged end of a cable assembly enters an unused powerreceptacle or port such as a 12 V power receptacle, the shield member atthe unplugged end may contact the power terminal or contact. Suchcontact may cause current to travel along the ground circuit of thecable assembly and to the device into which the opposite end of thecable assembly is plugged. Excessive current within the ground circuitmay cause damage depending upon the resistance of the cable assembly,the ground circuit and the components to which the ground circuit isconnected.

It would be desirable to provide a system and method which overcome thedisadvantages of the prior art ground circuit protection systems. Morespecifically, it would be desirable to provide a system and method forautomatically detecting overcurrent conditions and reducing oreliminating the overcurrent condition until the cause of the overcurrentcondition has been eliminated. The benefit of such a system would be toprotect the components and devices connected to the ground circuit andto permit normal operation after the cause of the overcurrent conditionhas been terminated.

SUMMARY

A ground overcurrent control system and methods of using same areprovided. In one aspect, a ground overcurrent control system includes acontroller, an electrical connector, a ground circuit, a switch element,a first sensor system, and a second sensor system. The electricalconnector includes a ground member and the ground circuit includes afirst section and a second section. The first section is electricallyconnected to the ground member of the electrical connector and thesecond section is electrically connected to a ground reference. Theswitch element is operatively positioned between the first section ofthe ground circuit and the second section of the ground circuit. Theswitch element is configured to operate in a first condition in whichthe first section and the second section are electrically connected anda second condition in which the first section and the second section areelectrically isolated. The first sensor system is configured to generatefirst signals indicative of a current passing through the first andsecond sections of the ground circuit while the switch element is in thefirst condition. The second sensor system is configured to generatesecond signals indicative of a voltage between the first section of theground circuit and the ground reference while the switch element is inthe second condition. The controller is configured to store a currentthreshold and a voltage threshold, receive the first signals from thefirst sensor system, and determine the current within the ground circuitbased upon the first signals while the switch element is in the firstcondition. Upon the current exceeding the current threshold, thecontroller is configured to generate a command to modify the switchelement from the first condition to the second condition and uponmodifying the switch element from the first condition to the secondcondition, receive the second signals from the second sensor. Thecontroller is further configured to determine the voltage between thefirst section of the ground circuit and the ground reference while theswitch element is in the second condition and, upon the voltage beingless than the voltage threshold, generate a command to modify the switchelement from the second condition to the first condition.

In another aspect, a method of controlling overcurrent on a groundcircuit is provided. The ground circuit includes a first section and asecond section with the first section being electrically connected to aground member of an electrical connector and the second section beingelectrically connected to a ground reference. A switch element isoperatively positioned between the first section of the ground circuitand the second section of the ground circuit and is configured tooperate in a first condition in which the first section and the secondsection are electrically connected and a second condition in which thefirst section and the second section are electrically isolated. Themethod includes storing a current threshold and a voltage threshold,while the switch element is in the first condition, receiving firstsignals from a first sensor system indicative of a current passingthrough the first and second sections of the ground circuit, anddetermining the current within the ground circuit based upon the firstsignals while the switch element is in the first condition. Upon thecurrent exceeding the current threshold, generating a command to modifythe switch element from the first condition to the second condition, andupon modifying the switch element from the first condition to the secondcondition, receiving second signals from a second sensor indicative of avoltage between the first section of the ground circuit and the groundreference. The method further includes determining the voltage betweenthe first section of the ground circuit and the ground reference whilethe switch element is in the second condition and, upon the voltagebeing less than the voltage threshold, generating a command to modifythe switch element from the second condition to the first condition.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention is illustrated by way of example and not limitedin the accompanying figures in which like reference numerals indicatesimilar elements and in which:

FIG. 1 illustrates a block diagram of a first exemplary embodiment of asystem incorporating the ground overcurrent control system as describedherein;

FIG. 2 illustrates a flowchart of a manner of operating the groundovercurrent control system of FIG. 1; and

FIG. 3 illustrates a block diagram of a second exemplary embodiment of asystem incorporating the ground overcurrent control system as describedherein.

DETAILED DESCRIPTION

The detailed description that follows describes exemplary embodimentsand is not intended to be limited to the expressly disclosedcombination(s). Therefore, unless otherwise noted, features disclosedherein may be combined together to form additional combinations thatwere not otherwise shown for purposes of brevity.

A block diagram of a first exemplary embodiment of a ground overcurrentcontrol system or module is indicated by dashed line 10 in FIG. 1.

In the first exemplary embodiment, the ground overcurrent control system10 is depicted as including a controller 15, one or more electricalconnectors 20, a ground circuit switch element 30, a first sensor system35, a second sensor system 40, and a ground or reference circuit 105.

The ground overcurrent control system 10 may be associated with andcontrolled by any type of controller 15 that is acceptable for itsintended application, as will be readily understood by one skilled inthe art. The controller 15 can be an electronic controller that operatesin a logical fashion to perform operations, execute control algorithms,store and retrieve data and other desired operations. The controller 15can include or access memory, secondary storage devices, processors, andany other components for running an application. The memory andsecondary storage devices can be in the form of read-only memory (ROM),random access memory (RAM) or integrated circuitry that is accessible bythe controller. Various other circuits can be associated with thecontroller such as power supply circuitry, signal conditioningcircuitry, driver circuitry, and other types of circuitry.

The controller 15 may be a single controller or may include more thanone controller disposed to control various functions and/or features.The term “controller” is meant to be used in its broadest sense toinclude one or more controllers, state machines, and/or microprocessorsthat may be associated with the ground overcurrent control system andthat may cooperate in controlling various functions and operationsrelated to or associated with the ground overcurrent control system 10.The functionality of the controller 15 can be implemented in hardwareand/or software without regard to the functionality. The controller 15may rely on one or more data maps relating to the operating conditionsand the operating environment of the ground overcurrent control system10 that may be stored in the memory. Each of these data maps may includea collection of data in the form of tables, graphs, and/or equations.Such data maps may be updated from time to time in any desired manner.As depicted, the controller 15 includes an application-specificintegrated circuit (ASIC) 16.

The ASIC 16 may be connected to a power source (not shown), such as abattery or the like, in a vehicle such that the power source deliverspower to the ASIC 16. The ground overcurrent control system 10 may forma part of another module such as multimedia connectivity module, asindicated by dashed line 17, that includes one or more additional ASICs18 with the ASIC 16 operatively connected to the ASICs 18 as depicted at100. The multimedia connectivity module 17 may be operatively connectedto an auto infotainment head end unit, another electronic control, orhost 19 (and thus is operatively connected to the ASIC 16) viaconnection 101. In another embodiment, the ground overcurrent controlsystem 10 may be separate from but operatively connected to themultimedia connectivity module 17. The multimedia connectivity module 17and/or host 19 may form a portion of the controller 15.

Ground overcurrent control system 10 includes one or more module-basedelectrical connectors 20. The electrical connectors 20 may have anyconfiguration. In one embodiment, the electrical connectors 20 may havean insulative housing 21 upon or in which a plurality of electricallyconductive signal contacts or terminals 22 are mounted. In FIG. 1, onlya portion of connection portions or tails of the electrically conductivesignal terminals 22 are visible. An electrically conductive ground orshield member 23 may generally surround the housing 21 and portions ofthe electrically conductive signal terminals 22. The ground member 23may include one or more connection portions 24. A mating end 25 of theground member 23 includes an opening (not shown) to form a receptacleinto which a mating electrical connector 55 may be inserted.

The ground or reference circuit 105 includes a first section 106 that iselectrically connected to one of the connection portions 24 of theground member 23 of electrical connector 20 such as at node 120. Asecond section 107 of the ground circuit 105 is connected to anovercurrent control system ground or reference 110 at node 121. As usedherein, the term “ground reference” refers to a ground or referencevoltage that may or may not be equal to zero. ASIC 16 is also depictedas including a connection to overcurrent control system ground reference110.

The second section 107 is also connected to other portions of the groundcircuit 105 such as a portion or segment 108 that extends from node 121and is electrically connected to the multimedia connectivity module 17and the multimedia connectivity module ground reference 111 at node 122.The second section 107 is also indirectly connected to a portion orsegment 109 of the ground circuit 105 within the host 19, which isconnected to the host ground reference 112 at node 123. In manyembodiments, each of the ground references 110-112 may be at the samepotential. In some instances, the ground circuit 105 of the multimediaconnectivity module 17 and the ground circuit of the host 19 may beinterconnected through a cable that forms the connection 101.

Switch element 30 is electrically connected to the first section 106 ofthe ground circuit 105 at node 124 and to the second section 107 at node125. Switch element 30 is configured to operate in a first or closedcondition in which the first section 106 of the ground circuit 105 andthe second section 107 of the ground circuit are electrically connectedand a second or open condition in which the first section and the secondsection of the ground circuit are electrically isolated. In other words,switch element 30 operates to open and close the connection between thefirst and second sections 106, 107 of the ground circuit 105. Asdepicted in FIG. 1, the switch element 30 is in the second conditionwith the first and second sections 106, 107 of the ground circuit 105electrically isolated.

Switch element 30 may be any type of switch that interrupts or divertsthe flow of current. In one embodiment, the switch element may be a FET,such as a MOSFET. In other embodiments, the switch element 30 may be anelectromechanical switch such as a relay. As depicted in FIG. 1, theswitch element 30 is a FET and is operatively connected to the ASIC 16.More specifically, the switch element 30 is actuated by signals from theASIC 16 via electrical connection 31.

The first sensor system, generally indicated at 35, operates to monitoror determine the amount of current passing through the first and secondsections 106, 107 of the ground circuit 105 when the switch element 30is closed. In the embodiment depicted in FIG. 1, the first sensor system35 includes a voltage sensor 36 and a resistor 37 associated with thevoltage sensor. The voltage sensor 36 extends between node 125 and theASIC 16. The resistor 37 extends between node 121 associated withovercurrent control system ground 110 and node 125 along the secondsection 107 of the ground circuit 105. Based upon a known value ofresistance of the resistor 37 and the voltage between node 125 and theovercurrent control system ground reference 110 at node 121, the amountof current passing through the resistor 37 may be determined. Thecurrent passing through the resistor 37 will be equal to the currentpassing through the switch element 30 (when in the closed condition) andthe second section 107 of the ground circuit 105.

The first sensor system 35 may be any type of sensor or system that willgenerate signals, directly or indirectly, indicative of the currentpassing through the switch element 30, when it is in its closedposition, and through the second section 107 of the ground circuit 105to the overcurrent control system ground reference 110. In theembodiment depicted in FIG. 1, the voltage sensor 36 may be configuredas an analog-to-digital converter. The value of the resistor 37 may beselected based upon the characteristics of the voltage sensor 36, theASIC 16, and other aspects of the ground circuit 105. For example, itmay be desirable for the resistance of the resistor 37 to be low enoughso that any current passing through the ground circuit 105 and theswitch element 30 passes through the resistor 37 to the ground reference110 rather than passing through the portion 108 of the ground circuit105 electrically connected to the multimedia connectivity module 17. Inother words, it may be desirable for the resistance of the resistor 37to be as low as or lower than the resistance of the portion 108 of theground circuit 105. In one embodiment, the resistance may beapproximately 0.01Ω. In other embodiments, the resistance may be between0.005-0.015Ω.

The first sensor system 35 may be configured in other manners. Forexample, rather than using an analog-to-digital converter to determinethe voltage at node 125 and using the ASIC 16 to compare the sensedvoltage to a threshold, the analog-to-digital converter may be replacedwith a voltage comparator. In such case, the voltage comparator may beselected or configured to generate a signal upon the voltage at node 125exceeding a threshold value. Once the threshold voltage has beenexceeded, the threshold current through the second section 107 of theground circuit 105 will also have been exceeded.

Still further, in another embodiment, the resistor 37 may be replaced bythe internal resistance of the switch element 30 and the connection ofthe voltage sensor 36 adjacent the second section 107 of the groundcircuit 105 moved from node 125 (i.e., after the switch element) to node124 (i.e., before the switch element). In such an example, the switchelement 30 may be a electronic switch such as a FET that includes aninternal resistance that may be readily measured or otherwisedetermined.

In still other embodiments, it may be possible to use a current sensoror a current comparator to determine when the current through the secondsection 107 of the ground circuit 105 exceeds a threshold current.

The second sensor system, generally indicated at 40, operates to monitoror determine the voltage at the first section 106 of the ground circuit105 once the switch element 30 is opened. In the embodiment depicted inFIG. 1, the second sensor system 40 includes a voltage sensor 41, and anauxiliary segment or leg 115 of the ground circuit 105 that iselectrically connected to node 124. The auxiliary segment 115 mayinclude a first resistor 42 and a second resistor 43 connected in seriesbetween the node 124 and an auxiliary ground reference 113. Auxiliaryground reference 113 may be at the same potential as the overcurrentcontrol system ground reference 110.

The voltage sensor 41 extends between node 127, located between thefirst resistor 42 and the second resistor 43, and the ASIC 16. In theembodiment depicted in FIG. 1, the voltage sensor 41 may be configuredas an analog-to-digital converter. The values of the first and secondresistors 42, 43 may be selected based upon the characteristics of thevoltage sensor 41, the ASIC 16, and other aspects of the ground circuit105. For example, in a first aspect, it may be desirable for theresistance of the first and second resistors 42, 43 to be high enough sothat, when the switch element 30 is closed, any current passing throughthe ground circuit 105 passes through the switch element 30 and theresistor 37 to the overcurrent control system ground reference 110rather than passing through the auxiliary segment 115 of the groundcircuit 105. In a second aspect, the resistances of the first resistor42 and the second resistor 43 may be selected so that the voltage to beanalyzed at node 127 will be within a desired range.

It should be noted that the resistance of resistor 37 is relativelysmall and the resistances of resistors 42 and 43 are relatively large topermit the ground circuit 105 to operate in a typical manner while theswitch element 30 is closed. With such a configuration, while the switchelement 30 is closed, essentially all of the current passing along theground circuit 105 will pass through the first and second sections 106,107 of the ground circuit 105 rather than the auxiliary segment 115 ofthe ground circuit 105.

The value of the first resistor 42 and the second resistor 43 may beselected based upon the characteristics of the voltage sensor 41, theASIC 16, and other aspects of the ground circuit 105. In one embodiment,the resistance of the first resistor 42 may be approximately 38K Ω andthe resistance of the second resistor 43 may be approximately 10K Ω.

The second sensor system 40 may be configured in other manners. Forexample, rather than using an analog-to-digital converter 41 todetermine the voltage at node 127 and using the ASIC 16 to compare thesensed voltage to a threshold voltage, the analog-to-digital convertermay be replaced with a voltage comparator. In such case, the voltagecomparator may be selected or configured to generate a signal upon thevoltage at node 127 exceeding a threshold value. Still further, it maybe possible to use a current sensor or a current comparator to determinewhen the voltage at node 127 exceeds the threshold voltage.

Module based electrical connector 20 is configured to be mated to acable assembly 50. Cable assembly 50 includes an electrical cable 51, afirst electrical connector 55, and a second electrical connector 60,with the electrical cable 51 extending between the first and secondelectrical connectors 55, 60. The electrical cable 51 includes aplurality of wires or conductors (not shown) therein. In someembodiments, the electrical cable 51 may include a shield or groundmember surrounding the wires or conductors. In other embodiments, one ormore of the wires within the electrical cable 51 may operate as a groundmember.

First electrical connector 55 includes a housing 56 upon or in which aplurality of electrically conductive signal contacts or terminals 57 aremounted. An electrically conductive ground or shield member 58 surroundsat least a portion of the housing 56 and signal terminals 57. Each ofthe signal terminals 57 may be electrically connected or terminated toone of the wires of the electrical cable 51. Wires or the shield orground member of the electrical cable 51 may be electrically connectedor terminated to the ground member 58 of the first electrical connector55.

Second electrical connector 60 includes a housing 61 upon or in which aplurality of electrically conductive signal contacts or terminals 62 aremounted. An electrically conductive ground or shield member 63 surroundsat least a portion of the housing 61 and signal terminals 62. Each ofthe terminals 62 may be electrically connected or terminated to one ofthe wires of the electrical cable 51. Wires or the shield or groundmember of the electrical cable 51 may be electrically connected orterminated to the ground member 63 of the second electrical connector60.

Each of the signal terminals 57 of the first electrical connector 55 maybe electrically connected to one of the signal terminals 62 of thesecond electrical connector 60 and the ground member 58 of the firstelectrical connector 55 is electrically connected to the ground member63 of the second electrical connector 60 through the electrical cable51. One or both of the first and second electrical connectors 55, 60 mayinclude electronic circuitry or components (not shown). Accordingly,there may not be a one-to-one correspondence between the terminals 57 ofthe first electrical connector 55 and the terminals 62 of the secondelectrical connector 60. In addition, under some circumstances, theelectronic circuitry or components within an electrical connector maypermit current to pass between the signal terminals of the connector andthe ground circuitry. Further, although referred to as signal terminals57, 62, in some embodiments, each of the signal terminals may not beused to transmit signals.

Upon inserting first electrical connector 55 into the module-basedelectrical connector 20 of the ground overcurrent control system 10, thesignal terminals 57 of the first electrical connector 55 will mate withand be electrically connected to the signal terminals 22 of themodule-based electrical connector 20. As a result, the signal terminals22 of the module-based electrical connector 20 will also be electricallyconnected to the signal terminals 62 of the second electrical connector60. In addition, the ground member 58 of the first electrical connector55 will mate with and be electrically connected to the ground member 23of the module-based electrical connector 20. As a result, ground member23 of the module-based electrical connector 20 will also be electricallyconnected to the ground member 63 of the second electrical connector 60.

In some operating environments, such as a vehicle, the first electricalconnector 55 of the cable assembly 50 may be inserted into or mated withthe module-based electrical connector 20 while the second electricalconnector 60 remains unmated. As a result of the flexibility ofelectrical cable 51, the second electrical connector 60 may moverelative to its operating environment. In some operating environments,the second electrical connector 60 may be in proximity to additionalpower sources such as 12 V cylindrical power outlets 65.

A 12 V cylindrical power outlet or receptacle 65 includes a cylindricalbody 66 that is electrically connected to a ground reference 67 at node130 and a center power contact 68 connected to a 12 V power supply 69 atnode 131. If the ground member 63 of the second electrical connector 60contacts the center power contact 68, current may be transmitted throughthe shield or other conductors of the electrical cable 51 to the groundmember 58 of the first electrical connector 55. The electricalconnection between the ground member 58 of the first electricalconnector 55 and the ground member 23 of the module-based electricalconnector 20 will result in current on the ground circuit 105 of theground overcurrent control system 10.

In some operating environments, a power source such as the 12 Vcylindrical power outlet 65 may provide twenty (20) A of current and maybe coupled with a fuse that permits the transmission of current far inexcess of twenty (20) A. For example, in one application, such a 12 Vcylindrical power outlet 65 may be used with a fuse that may permittransmission of sixty (60) A for two seconds before blowing or trippingthe fuse. The cable assembly 50, the module-based electrical connector20, the first and second electrical connectors 55, 60, components of themultimedia connectivity module 17 and the host 19 as well as theinterconnections therebetween may not be rated or configured to handlelarge amounts of current. Accordingly, inadvertent and/or undesiredtransmission of large amounts of current through the aforementionedcomponents and the ground circuit 105 may result in damage to suchcomponents.

The ground overcurrent control system 10 is operative to respond toconditions in which the current passing along the ground circuit 105 andcomponents connected thereto exceeds a threshold current in order toprotect the cable assembly 50, the module-based electrical connector 20,the first and second electrical connectors 55, 60, components of themultimedia connectivity module 17 and the host 19 as well as theinterconnections therebetween.

FIG. 2 depicts a flowchart of one manner of operation of the groundovercurrent control system 10. At stage 70, the current thresholdcorresponding to the maximum current that may pass through the groundcircuit 105 before actuating the switch element 30 may be set or storedwithin the controller 15. In addition, the voltage thresholdcorresponding to the maximum voltage permitted at the ground connection24 of the module-based electrical connector 20 before the switch element30 will be closed during the operation of the ground overcurrent controlsystem 10 may be set or stored within the ASIC 16. The current thresholdand the voltage threshold may be set or stored in any manner. Forexample, the thresholds may be set or stored during the manufacture ofthe ground overcurrent control system 10 or any other time as desired tocontrol the operation of the ground overcurrent control system 10.

At stage 71, the device or system that includes the ground overcurrentcontrol system 10, such as the multimedia connectivity module 17 may beoperated. Data may be received at stage 72 by the ASIC 16 from thevoltage sensor 36. The data may be received at any desired rate orfrequency. In one example, the data may be received once everymillisecond. At stage 73, the ASIC 16 may determine the current passingthrough the first and second sections 106, 107 of the ground circuit105. To do so, the ASIC 16 may receive signals from the voltage sensor36 indicative of the voltage between node 125 and overcurrent controlsystem ground reference 110 across the resistor 37. Based upon thevoltage and the known resistance of resistor 37, the current through thefirst and second sections 106, 107 of the ground circuit 105 may bedetermined.

In some applications, the ASIC 16 may be configured to analyze aplurality of data samples to determine the current passing through thefirst and second sections 106, 107 of the ground circuit 105. Suchanalysis may be performed in any desired manner. In one embodiment, theASIC 16 may analyze a plurality of data samples over a predeterminedperiod of time and utilize an average of the received data samples. Inother embodiments or in addition, the ASIC 16 may analyze a plurality ofdata samples over a predetermined period of time and utilize the maximumof the receive data samples. In one example, the ASIC 16 may analyzegroups of ten data samples to generate a current value. In someinstances, procedures or methods may be utilized to eliminate erroneousdata samples. Other processes are contemplated.

Upon determining the sensed current passing through the first and secondsections 106, 107 of the ground circuit 105, the ASIC 16 may compare thesensed current to the current threshold at decision stage 74 todetermine whether the sensed current exceeds the current threshold. Ifthe sensed current does not exceed the current threshold, the device orsystem such as the multimedia connectivity system 17 that includes theground overcurrent control system 10 may continue to operate and stages71-74 repeated.

If the sensed current exceeds the current threshold, the ASIC 16generates at stage 75 a signal along the electrical connection 31 toopen the switch element 30. Opening the switch element 30 will interruptthe passage of current from the first section 106 of the ground circuit105 to the second section 107 of the ground circuit 105. Suchinterruption of the current along the ground circuit 105 will eliminateor substantially reduce the current along the first section 106 andeliminate the current along the second section 107 as well as theadditional components of the system connected to the second section 107such as the segment 108 of the multimedia connectivity module 17 and thehost 19. Accordingly, the ground overcurrent control system 10 willprotect the module-based electrical connector 20, the cable assembly 50,including the first and second electrical connectors 55, 60, componentsof the multimedia connectivity module 17 and the host 19 as well as theinterconnections therebetween from damage due to excessive currentpassing along the ground circuit 105.

By opening the switch element 30, and the module-based electricalconnector 20 to which the cable assembly 50 is connected will no longerbe connected to the second section 107 of ground circuit 105. Groundovercurrent control system 10 further includes functionality to monitorthe ground circuit 105 and restore the normal operation thereof once theconfiguration or issue causing the ground overcurrent condition has beeneliminated. In particular, once the switch element 30 is open,relatively small amounts of current may pass through the cable assembly50 to the module-based electrical connector 20 and along the auxiliaryground segment 115 until reaching the auxiliary ground reference 113. Byconfiguring the first and second resistors 42, 43 to have a relativelylarge resistance, the current passing through the auxiliary groundsegment 115 will be relatively small.

With the switch element 30 in its open position, data may be received atstage 76 by the ASIC 16 from the voltage sensor 41. As discussed abovewith respect to voltage sensor 36, the data from voltage sensor 41 maybe received at any desired rate or frequency. In one example, the datamay be received once every millisecond. At stage 77, the ASIC 16 maydetermine the voltage at the node 127. To do so, the ASIC 16 may receivesignals from the voltage sensor 41 indicative of the voltage betweennode 127 and auxiliary ground reference 113 and across the secondresistor 43. Based upon the voltage and the known resistance of thefirst and second resistors 42, 43, the voltage at the first section 106of the ground circuit 105 may be determined.

As with the analysis of the current through the first and secondsections 106, 107 of the ground circuit 105, in some applications, theASIC 16 may be configured to analyze a plurality of data samples todetermine the voltage at the first section 106 of the ground circuit105. Such analysis may be performed in any desired manner. In oneembodiment, the ASIC 16 may analyze a plurality of data samples over apredetermined period of time and utilize an average of the received datasamples. In other embodiments or in addition, the ASIC 16 may analyze aplurality of data samples over a predetermined period of time andutilize the maximum of the receive data samples. In one example, theASIC 16 may analyze groups of ten data samples to generate a voltagevalue. In some instances, procedures and methods may be utilized toeliminate erroneous data samples. Other processes are contemplated.

Upon determining the voltage at the first section 106 of the groundcircuit 105, the ASIC 16 may compare the sensed voltage to the voltagethreshold at decision stage 78 to determine whether the sensed voltageis below the voltage threshold. If the sensed voltage is not less thanthe voltage threshold, the switch element 30 may remain open and stages76-78 repeated.

If the sensed voltage is less than the voltage threshold, the ASIC 16may generate at stage 79 a signal along the electrical connection 31 toclose the switch element 30. Closing the switch element 30 willreconnect the first and second sections 106, 107 of the ground circuit105 and permit the passage of current from the first section 106 to thesecond section 107. Such reconnection of first and second sections 106,107 of the ground circuit 105 will permit the operation of themodule-based electrical connector 20 and the multimedia connectivitymodule 17 as desired and stages 71-74 repeated.

Other embodiments are contemplated. For example, other embodiments fordetermining when to close the switch element 30 may be provided. In oneembodiment, the ASIC 16 may include a timer associated therewith and theswitch element 30 closed after a predetermined period of time afteropening the switch element 30. In another embodiment, the switch element30 may remain open until a re-setting event occurs. For example, are-setting event may be an interruption in power to the multimediaconnectivity module 17 which may be caused by turning off and turning onthe ignition or the auxiliary power of a vehicle. In such case, the ASIC16 may re-set the switch element 30 to its closed position uponinitializing power to the ground overcurrent control system 10 directlyor indirectly such as by initializing power to the multimediaconnectivity module 17. To do so, upon powering up the groundovercurrent control system 10 (or the multimedia connectivity module17), the ASIC 16 may generate a command to modify the switch element 30from the open position to the closed position to ensure that the switchelement 30 is closed.

In another embodiment, a multimedia connectivity module (not shown) mayinclude a plurality of module-based electrical connectors 20 with eachconnector being connected to a ground overcurrent control system 10.Referring to FIG. 3, in still another embodiment, multimediaconnectivity module 17 may include a plurality of module-basedelectrical connectors 20 with the connectors being connected to a singleground overcurrent control system 210. Like components are indicated bylike reference numbers. In some applications and under somecircumstances, a signal terminal 62, such as a V_(bus) signal terminal,of one of the electrical connectors of cable assembly 50, such as secondelectrical connector 60, may be electrically connected throughelectronic components in the connector 60 to the ground circuit 105 ofthe connector 20. Upon excessive current passing through one (or afirst) of the cable assemblies 50 to the ground circuit 105, the switchelement 30 will be moved from its closed position to its open position.However, if the other (or second) cable assembly 50 is connected to anelectronic device such as a mobile phone, the excessive current on thefirst section 106 of the ground circuit 105 due to the first cableassembly may pass through the ground circuit of the second cableassembly and into the V_(bus) signal terminal of the second cableassembly. The excessive current may pass through the V_(bus) signalterminal and into the connected electronic device, potentially damagingthe electronic device.

In order to avoid this result, the ground overcurrent control system 210may include signal switch elements 211 to disconnect one or more signalterminals 22 (e.g., the V_(bus) signal terminal) from the signalconductors 212 to which they are connected. More specifically, eachsignal switch element 211 is electrically connected to one of the signalterminals 22 and a signal conductor 212 of the ground overcurrentcontrol system 210.

Each signal switch element 211 is configured to operate in a first orclosed condition in which a signal terminal 22 and a signal conductor212 are electrically connected and a second or open condition in whichthe signal terminal 22 and a signal conductor 212 are electricallyisolated. In other words, each signal switch element 211 operates toopen and close the connection between a signal terminal 22 and a signalconductor 212. As depicted in FIG. 3, each of the signal switch elements211 is in the second condition with its signal terminal 22 and itsrespective signal conductor 212 electrically isolated.

Signal switch element 211 may be any type of switch that interrupts ordiverts the flow of current. In one embodiment, the signal switchelements may be FETs, such as MOSFETs. In other embodiments, each signalswitch element 211 may be an electromechanical switch such as a relay.As depicted in FIG. 3, the signal switch elements 211 are FETs and areoperatively connected to the ASIC 16. More specifically, the signalswitch elements 211 are actuated by signals from the ASIC 16 viaelectrical connection 213.

Operation of the ground overcurrent control system 210 may besubstantially identical to that described above with respect to theground overcurrent control system 10. However, upon determining that thecurrent through the ground circuit switch element 30 exceeds the currentthreshold, the ASIC 16 sends commands via electrical connection 213 toopen the signal switch elements 211 prior to sending a command to openthe ground circuit switch element 30.

After the signal switch elements 211 are opened, the ground circuitswitch element 30 may be opened. By opening the signal switch elements211 prior to opening the ground circuit switch element 30, excessivecurrent in the ground circuit 105 will not be transmitted through theground circuit 105 of the connector 20 and into the signal terminal 22such as a V_(bus) terminal.

Once the ground circuit switch element 30 is opened, the groundovercurrent control system 210 monitors the voltage at node 127 asdescribed above with respect to ground overcurrent control system 10 todetermine whether an excess current condition remains on section 106 ofground circuit 105. Once the excess current condition has beeneliminated, the ground circuit switch element 30 may be closed and thenthe signal switch elements 211 closed.

Other embodiments similar to the ground overcurrent control system 210are contemplated. For example, other manners of re-setting the groundcircuit switch element 30 and the signal switch elements 211 may beutilized such as those additional manners or re-setting the groundcircuit switch element 30 as discussed above with respect to groundovercurrent control system 10.

While the disclosure is described and illustrated with the groundovercurrent control system 10 being part of the multimedia connectivitymodule 17, the ground overcurrent control system 10 may have anyconfiguration such as part of a larger electronic unit, module, orsystem or as a standalone device.

While the disclosure is described and illustrated with regard to theground overcurrent control system 10 utilizing an ASIC 16, it is to beunderstood than any other appropriate means, such as a microprocessor,state machine, or any discrete electronic solution, could be utilized.

While the disclosure is described and illustrated with regard to havinga first and second sensor systems 35, 40, it is to be understood that asingle sensor system performing the functionality of both the first andsecond sensor systems may be utilized.

While the disclosure is described and illustrated as having exemplaryelectrical connectors 20 and power outlet or receptacle 65, it is to beunderstood that other electrical connectors and power outlets could beprovided as desired, and the disclosure should not be limited to theexemplary connectors and power outlets.

While the disclosure is described and illustrated as having resistors37, 42, 43 having exemplary resistance values, it is to be understoodthat other resistance values may be used as desired.

The disclosure provided herein describes features in terms of preferredand exemplary embodiments thereof. Numerous other embodiments,modifications and variations within the scope and spirit of the appendedclaims will occur to persons of ordinary skill in the art from a reviewof this disclosure.

What is claimed is:
 1. A ground overcurrent control system, the groundovercurrent control system comprising: an electrical connector, theelectrical connector including a ground member; a ground circuit, theground circuit including a first section and a second section, the firstsection being electrically connected to the ground member of theelectrical connector, the second section being electrically connected toa ground reference; a switch element operatively positioned between thefirst section of the ground circuit and the second section of the groundcircuit, the switch element being configured to operate in a firstcondition in which the first section and the second section areelectrically connected and a second condition in which the first sectionand the second section are electrically isolated; a first sensor systemconfigured to generate first signals indicative of a current passingthrough the first and second sections of the ground circuit while theswitch element is in the first condition; a second sensor systemconfigured to generate second signals indicative of a voltage betweenthe first section of the ground circuit and the ground reference whilethe switch element is in the second condition; and a controllerconfigured to: store a current threshold and a voltage threshold;receive the first signals from the first sensor system; determine thecurrent within the ground circuit based upon the first signals while theswitch element is in the first condition; upon the current exceeding thecurrent threshold, generate a command to modify the switch element fromthe first condition to the second condition; upon modifying the switchelement from the first condition to the second condition, receive thesecond signals from the second sensor; determine the voltage between thefirst section of the ground circuit and the ground reference while theswitch element is in the second condition; and upon the voltage beingless than the voltage threshold, generate a command to modify the switchelement from the second condition to the first condition.
 2. The systemof claim 1, wherein the switch element is a MOSFET.
 3. The system ofclaim 1, wherein the first sensor system comprises a voltage sensor. 4.The system of claim 3, wherein the first sensor system further comprisesa resistance member.
 5. The system of claim 4, wherein the resistancemember is a discrete resistor disposed between the switch element andthe ground reference.
 6. The system of claim 4, wherein switch elementhas an internal resistance and the resistance member is the internalresistance of the switch member.
 7. The system of claim 1, wherein thesecond sensor system comprises a voltage sensor.
 8. The system of claim1, wherein each of the first sensor system and the second sensor systemcomprises an analog-to-digital converter.
 9. The system of claim 1,wherein the ground member of the electrical connector includes a shieldthat generally surrounds the electrical connector and a connectionportion.
 10. The system of claim 1, further including an auxiliaryground segment extending between the first section of the ground circuitand the ground reference, the auxiliary ground segment including atleast one resistor.
 11. The system of claim 10, wherein the auxiliaryground segment includes a first resistor and a second resistor, thefirst and second resistors being arranged in series along the auxiliaryground segment, and the second sensor system is configured to generatethe second signals indicative of the voltage between the first resistorand the ground reference.
 12. The system of claim 1, further comprisinga signal circuit and a signal switch element, and the electricalconnector further comprising a signal contact; the signal circuitincluding a first section and a second section, the first section of thesignal circuit being electrically connected to the signal contact of theelectrical connector, the signal switch element being operativelypositioned between the first section of the signal circuit and thesecond section of the signal circuit, the signal switch element beingconfigured to operate in a first condition in which the first sectionand the second section are electrically connected and a second conditionin which the first section and the second section are electricallyisolated, and the controller is further configured to: upon the currentexceeding the current threshold, generate a command to modify the signalswitch element from the first condition to the second condition; andupon the voltage being less than the voltage threshold, generate acommand to modify the signal switch element from the second condition tothe first condition.
 13. The system of claim 12, wherein upon thecurrent exceeding the current threshold, the controller is furtherconfigured to generate a command to modify the signal switch elementfrom the first condition to the second condition before generating thecommand to move the switch element from the first condition to thesecond condition.
 14. The system of claim 13, wherein upon the voltagebeing less than the voltage threshold, the controller is furtherconfigured to generate a command to modify the signal switch elementfrom the second condition to the first condition after generating acommand to move the switch element from the second condition to thefirst condition
 15. A method of controlling overcurrent on a groundcircuit, the ground circuit including a first section and a secondsection, the first section being electrically connected to a groundmember of an electrical connector, the second section being electricallyconnected to a ground reference, and a switch element being operativelypositioned between the first section of the ground circuit and thesecond section of the ground circuit, the switch element beingconfigured to operate in a first condition in which the first sectionand the second section are electrically connected and a second conditionin which the first section and the second section are electricallyisolated, the method comprising: storing a current threshold and avoltage threshold; while the switch element is in the first condition,receiving first signals from a first sensor system indicative of acurrent passing through the first and second sections of the groundcircuit; determining the current within the ground circuit based uponthe first signals while the switch element is in the first condition;upon the current exceeding the current threshold, generating a commandto modify the switch element from the first condition to the secondcondition; upon modifying the switch element from the first condition tothe second condition, receiving second signals from a second sensorindicative of a voltage between the first section of the ground circuitand the ground reference; determining the voltage between the firstsection of the ground circuit and the ground reference while the switchelement is in the second condition; and upon the voltage being less thanthe voltage threshold, generating a command to modify the switch elementfrom the second condition to the first condition.
 16. The method ofclaim 15, wherein the first sensor system comprises a voltage sensor.17. The method of claim 16, wherein the first sensor system furthercomprises a resistance member.
 18. The method of claim 15, furtherincluding an auxiliary ground segment extending between the firstsection of the ground circuit and the ground reference, the auxiliaryground segment including at least one resistor.
 19. The method of claim18, wherein the auxiliary ground segment includes a first resistor and asecond resistor, the first and second resistors being arranged in seriesalong the auxiliary ground segment, and wherein the second signals areindicative of the voltage between the first resistor and the groundreference.
 20. A ground overcurrent control system, the groundovercurrent control system comprising: an electrical connector, theelectrical connector including a ground member; a ground circuit, theground circuit including a first section and a second section, the firstsection being electrically connected to the ground member of theelectrical connector, the second section being electrically connected toa ground reference; a switch element operatively positioned between thefirst section of the ground circuit and the second section of the groundcircuit, the switch element being configured to operate in a firstcondition in which the first section and the second section areelectrically connected and a second condition in which the first sectionand the second section are electrically isolated; a first sensor systemconfigured to generate first signals indicative of a current passingthrough the first and second sections of the ground circuit while theswitch element is in the first condition; and a controller configuredto: store a current threshold; generate a command to modify the switchelement from the second condition to the first condition upon initiallyproviding power to the ground overcurrent control system; receive thefirst signals from the first sensor system; determine the current withinthe ground circuit based upon the first signals while the switch elementis in the first condition; and upon the current exceeding the currentthreshold, generate a command to modify the switch element from thefirst condition to the second condition.
 21. A ground overcurrentcontrol system, the ground overcurrent control system comprising: firstand second electrical connectors, each electrical connector including aground member and a signal contact; a ground circuit, the ground circuitincluding a first section and a second section, the first section beingelectrically connected to the ground members of the first and secondelectrical connectors, the second section being electrically connectedto a ground reference; first and second signal circuits, each signalcircuit including a first section and a second section, the firstsection of the first signal circuit being electrically connected to thesignal contact of the first electrical connector, the first section ofthe second signal circuit being electrically connected to the signalcontact of the second electrical connector; a ground circuit switchelement operatively positioned between the first section of the groundcircuit and the second section of the ground circuit, the ground circuitswitch element being configured to operate in a first condition in whichthe first section and the second section are electrically connected anda second condition in which the first section and the second section areelectrically isolated; first and second signal switch elements, eachsignal switch element being operatively positioned between the firstsection of one of the signal circuits and the second section of the samesignal circuit, each signal switch element being configured to operatein a first condition in which the first section of one of the signalcircuits and the second section of the same signal circuit areelectrically connected and a second condition in which the first sectionof one of the signal circuits and the second section of the same signalcircuit are electrically isolated; a first sensor system configured togenerate first signals indicative of a current passing through the firstand second sections of the ground circuit while the ground circuitswitch element is in the first condition; a second sensor systemconfigured to generate second signals indicative of a voltage betweenthe first section of the ground circuit and the ground reference whilethe ground circuit switch element is in the second condition; and acontroller configured to: store a current threshold and a voltagethreshold; receive the first signals from the first sensor system;determine the current within the ground circuit based upon the firstsignals while the ground circuit switch element is in the firstcondition; upon the current exceeding the current threshold, generate acommand to modify the signal switch element from the first condition tothe second condition; after modifying the signal switch element from thefirst condition to the second condition, generate a command to modifythe ground circuit switch element from the first condition to the secondcondition; upon modifying the ground circuit switch element from thefirst condition to the second condition, receive the second signals fromthe second sensor; determine the voltage between the first section ofthe ground circuit and the ground reference while the ground circuitswitch element is in the second condition; upon the voltage being lessthan the voltage threshold, generate a command to modify the groundcircuit switch element from the second condition to the first condition;and after modifying the ground circuit switch element from the secondcondition to the first condition, generate a command to modify thesignal switch element from the second condition to the first condition.